Optical device utilizing ballistic zoom and methods for sighting a target

ABSTRACT

A method of sighting a target includes receiving an initial condition of an optical device. The initial condition includes a size of a ranging element and a range associated with the size of the ranging element. The method further includes receiving a ballistic information and receiving an image from an imaging sensor. At least a portion of the image is displayed on a display. The ranging element is overlaid on the displayed portion of the image. A first zoom input is received to set a first zoom value that corresponds to a first distance from the optical device. The method also includes determining a first projectile position based on the first distance and the ballistic information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 13/786,383, filed Mar. 5, 2013, and entitled “Digital TargetingScope Apparatus,” which is a continuation-in-part of U.S.Non-Provisional application Ser. No. 13/412,506, filed Mar. 5, 2012,entitled “Dscope Aiming Device,” the disclosures of which are herebyincorporated by reference herein in their entireties.

INTRODUCTION

When making a long range shot with a firearm, the shooter must firstdetermine a firing solution based on distance to target (Range), bulletdrop due to the flight characteristic of the bullet and gravity (Drop),and crosswind component of the wind that is blowing at the time offiring (Windage).

Typically, the shooter will have a chart taped to the side of hisweapon, or will have memorized the values for each of the correctionsi.e. Drop and Windage at various Ranges and wind velocities. The shootermust then make a correction for each of these component values. Twomethods are commonly used for this purpose. The first is to manuallyadjust the turrets on an optical aiming device so that the reticle isdirecting the shooter to the corrected target position. The secondalternative is to use what is commonly called “Holdover” by thoseskilled in the art. There are many types of optical aiming devices thathave graduated reticles for this purpose. The shooter places the targetat a different position on the reticle based on its graduations.

There are numerous “Optical solutions” to the “Automatic Firingsolution” problem cited in previous patents; however, few seldom survivein the marketplace because of the high cost of automatically movingoptical components and the difficulty of maintaining accuracy withrepeated impact from a weapon.

SUMMARY

A first embodiment of the targeting device or apparatus in accordancewith the present disclosure includes an image sensor and a lens foracquiring video images of objects at which the aiming device is aimed;an image processor; a tilt sensor for sensing the force of gravity inrelation to the aiming device; a display component for displaying thevideo images captured by the image sensor, and processed by the imageprocessor; a eyepiece lens to allow the user to view the displaycomponent; a pressure and temperature sensor to sense atmosphericconditions, and suitable means to house said components.

The apparatus provides a completely “Solid state digital” and “HandsFree” solution to the task of accurately firing a weapon at long range.The shooter is able to input all of the necessary information to make along range shot at the time of firing without removing his hands fromthe weapon, by simply tilting the weapon from side to side.

A predetermined threshold angle defines the tilt function. For purposesof explanation, let us say this is 10 degrees. If the tilt angle of theweapon is less than 10 degrees in either direction i.e. left or right, acalculation is made for cross-windage adjustment. A representation ofthe amount of cross-windage adjusted for, is superimposed; along with asuitable crosshair symbol to define aim point, on a video imagepresented to the shooter. If the tilt angle is greater than 10 degreesin either direction, a range number superimposed on the video image, isprogressively increased or decreased dependent on the direction andmagnitude of the tilt angle greater than 10 degrees. The field of viewi.e. (the magnification power) of the video image presented to theshooter is simultaneously increased or decreased in relation to theRange number, if the field of view is within field of view limitsdefined by the front lens and the image sensor.

A Range finding circle is also superimposed on the video image. Thiscircle represents a predetermined target size. The circle remains afixed size on the display component, if the field of view is greaterthan its minimum. If the field of view is at minimum, the Range findingcircle size is progressively adjusted to a smaller size in relation tothe Range setting. To find the distance to target, the shooter adjuststhe range setting by tilting the weapon more than 10 degrees left orright until the target fits the range finding circle.

As described above, the apparatus provides a durable aiming device withno visible external controls. All ballistic calculations necessary forlong-range shooting are performed automatically in relation to internalsensors and settings performed by tilting the weapon; thereby, renderinga simple and easy to use aiming device.

Another embodiment in accordance with the present disclosure is adigital targeting scope apparatus that includes a tubular housing havinga central axis and a first end and a second end and an interchangeabledigital camera module carried by the first end of the housing. Thecamera module includes at least one focusing lens axially spaced from animage sensor mounted normal to a lens axis on a sensor circuit boardwithin the camera module. An image projected by the lens focuses at apredetermined location on the sensor. A control/display module having alongitudinal axis is removably fastened to the second end of thehousing. The control/display module is electrically connected to thecamera module through a connector on the sensor circuit board of thecamera module. Connection is made when the control/display module isinstalled in the second end of the housing. The control/display modulehas a control portion including a circuit board and a display componentmounted thereon and includes a display portion housing an eyepiece lensassembly aligned with the display component.

The control portion of the control/display module preferably has a powersource, a tilt sensor, an external computer connector, an imageprocessor, a memory and a pair of switches all connected to a printedcircuit on a printed circuit board oriented axially in thecontrol/display module. The camera module and control/display module arecoaxially aligned in the tubular housing. The control/display module isconfigured to permit a user to select between settable preprogrammedparameters when the control/display module is separated from the cameramodule and rotated about its longitudinal axis. The selection of one ormore of the preprogrammed parameters is made by actuation of one or moreof the pair of switches.

A tilt sensor in the control/display module is configured to measure atilt angle of the device about the housing axis and cause the imageprocessor to produce an adjusted target image in response to themeasured tilt angle. The image processor is configured to generate achange in display image field of view upon receipt from the tilt sensorof a measured tilt angle greater than a threshold angle. A tilt anglegreater than zero and less than the threshold angle causes a windageadjustment indicator in the display image field of view to changeposition.

The control/display module is configured to permit a user to selectbetween settable preprogrammed parameters when the control/displaymodule is separated from the camera module and horizontally held androtated about its longitudinal axis.

In one aspect, the technology relates to a method of sighting a target,the method including: receiving an initial condition of an opticaldevice, wherein the initial condition includes a size of a rangingelement and a range associated with the size of the ranging element;receiving a ballistic information; receiving an image from an imagingsensor; displaying at least a portion of the image on a display;overlaying the ranging element on the displayed portion of the image;receiving a first zoom input to set a first zoom value, wherein thefirst zoom value corresponds to a first distance from the opticaldevice; and determining a first projectile position based on the firstdistance and the ballistic information. In an embodiment, the methodfurther includes displaying a first region of interest based at least inpart on the first projectile position and the first zoom value. Inanother embodiment, the method further includes displaying a firstsymbol corresponding to the first projectile position. In yet anotherembodiment, the method further includes: receiving a maximum zoom inputto set a maximum zoom value, wherein the maximum zoom value is definedby an image sensor region of interest and a display region of interest;displaying a maximally magnified image associated with the maximum zoomvalue; receiving a second zoom input to set a second zoom value, whereinthe second zoom value corresponds to a second distance from the opticaldevice; calculating a size of an adjusted ranging element; superimposingthe adjusted ranging element on the displayed maximally magnified image;determining a second projectile position based on the second distanceand the ballistic information; and displaying a second region ofinterest based at least in part on the second projectile position andthe second zoom value. In still another embodiment, the method furtherincludes displaying a second symbol corresponding to the secondprojectile position.

In another embodiment of the above aspect, the first symbol has at leastone of a point of impact at the target and a guide symbol. In anembodiment, the first projectile position determination operation isbased at least in part on a crosswind input. In another embodiment, thefirst projectile position determination operation is based at least inpart on a projectile information input, an ambient temperature input, aninclination input, a tilt input, a muzzle exit velocity input, and abarometric pressure input. In yet another embodiment, the imaging sensorhas a camera.

In another aspect, the technology relates to a method of sighting atarget, the method including: receiving a ballistic information;receiving an image from an imaging sensor; receiving a zoom value;calculating a projectile trajectory based at least in part on theballistic information; and displaying a region of interest based on thezoom value, wherein the region of interest corresponds at least in partto the projectile trajectory. In an embodiment, the method furtherincludes determining a range to the target. In another embodiment, thedetermination operation includes: displaying at least a portion of theimage on a display; and superimposing a ranging element on the portionof the image. In yet another embodiment, the method further includes:receiving a zoom input, wherein the zoom input has an updated zoomvalue; and displaying an updated region of interest based on the updatedzoom value.

In yet another aspect, the technology relates to a method of sighting atarget, the method includes: receiving an image from an image sensor;displaying at least a portion of the received image, wherein thedisplayed portion has a displayed field of view; displaying a rangingelement with a fixed size in relation to the displayed field of view;receiving a target size input; receiving a zoom input to set a zoomvalue; calculating a range to a target based at least in part on thetarget size input and the zoom value. In an embodiment, the target sizeinput has a default target size input. In another embodiment, thereceiving target size input includes receiving the target size inputfrom a storage device. In yet another embodiment, the target size inputis selected from a plurality of predetermined target sizes.

In still another aspect, the technology relates to an apparatus forsighting a target, the apparatus includes: a housing; a display; animaging sensor; and a controller configured to selectively operate theapparatus in a default zoom mode and a ballistic zoom mode, wherein whenin the default zoom mode, an increase in a zoom level changes a field ofview along an optical path from the apparatus to the target, and whereinwhen in the ballistic zoom mode, the increase in the zoom level changesthe field of view along a ballistic path from the apparatus. In anembodiment, wherein in the default zoom mode, a symbol associated with aprojectile point of impact is displayed on the display, wherein aposition of the symbol on the display changes based on the zoom level.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present technology, as well as thetechnology itself, can be more fully understood from the followingdescription of the various embodiments, when read together with theaccompanying drawings, in which:

FIG. 1 is a partial, cross-sectional, schematic view of one embodimentof a digital targeting scope in accordance with the present disclosure.

FIG. 2 illustrates one embodiment of a target image overlay of thedigital targeting scope of FIG. 1.

FIG. 3 is a side view of another embodiment of a digital targeting scopein accordance with the present disclosure.

FIG. 4 is a partial, cross-sectional, schematic view of the digitaltargeting scope of FIG. 3.

FIG. 5 is a separate perspective view a control/display module of thedigital targeting scope of FIG. 3.

FIG. 6 is another perspective view of the control/display module asshown in FIG. 5.

FIG. 7 is a separate perspective view of the control portion of thecontrol/display module of FIG. 6.

FIG. 8 is a perspective view of the control portion of thecontrol/display module of FIG. 6, showing the sensor circuit boardconnected to the control portion.

FIG. 9 is a separate, cross-sectional, schematic view of aninterchangeable camera module of the embodiment of the digital targetingscope shown in FIG. 3.

FIG. 10 illustrates four representative displays provided by thecontrol/display module of the digital targeting scope of FIG. 3.

FIG. 11 is a simplified representation of the effect of gravity on theflight of a bullet.

FIGS. 12A-12C depict comparisons between captured field of view versusdisplayed view for an aiming device using ballistic zoom technology.

FIG. 13A depicts a region of interest for various magnifications of atraditional optical zoom system.

FIG. 13B depicts a region of interest for various magnifications of aballistic zoom system in accordance with one embodiment of the presentdisclosure.

FIG. 14 depicts a relationship between a field of view and a fixed sizeranging element.

FIGS. 15-18 depict methods of sighting a target.

FIG. 19 illustrates the process of initially aligning or sighting in theapparatuses shown in FIG. 1 and in FIG. 3 on a weapon such as a rifle.

FIG. 20 illustrates the process of determining the muzzle velocity (MV)and ballistic characteristic (BC) values for the apparatuses shown inFIG. 1 and FIG. 3 on a specific weapon such as a rifle for variousdistances.

DETAILED DESCRIPTION

Reference will now be made in detail to the accompanying drawings, whichat least assist in illustrating pertinent embodiments of the newtechnology provided for by the present disclosure.

Referring now to FIG. 1, one embodiment of a digital targeting scopesystem 100 is illustrated. In the illustrated embodiment, the system 100includes an elongated, hollow, tubular housing 101 having a front endand rear end. The housing may be fabricated from anodized aluminum orthe like. A front lens 102 and an image sensor 103 are mounted proximalthe front end of the housing 101. The front lens 102 is mounted so as tofocus light from a target onto the image sensor 103. An image processor104, a tilt sensor 105, and batteries 106 are mounted within the tubularhousing 101. The image sensor 103 and tilt sensor 105 are in electricalcommunication with the image processor 104. A control/display module 108and an image display component 109 are mounted proximal the rear end ofthe housing 101. The image display component 109 is in electricalcommunication with the image processor 104. The housing 101 may alsoinclude an integral mounting system (not pictured) for the purpose ofmounting the aiming device 100 to a weapon (e.g., a rifle).

In this exemplary embodiment, the image sensor 103 is operable to obtainraw image data of the target. The image processor 104 is operable toreceive the raw image data from the image sensor 103 and produce atarget image based thereon. The image display component 109 is operableto receive the target image from the image processor 104 and display thetarget image to a user, which may facilitate aiming of the weapon.

The tilt sensor 105 is operable to measure the tilt angle of the aimingdevice 100 and produce angular position data based thereon. As usedherein, “tilt angle” means the rotational orientation of the aimingdevice 100 about the center axis of the tubular housing 101. Tilt angleis expressed as the amount, in degrees, of rotational displacement(i.e., angular displacement) of the device while positioned on ahorizontal axis through the device from a reference orientation (e.g.,vertical). In one embodiment, the tilt sensor is an accelerometer. Aneye sensor 110 a disposed proximate the ocular lens 110 and in operablecommunication with the processor 104 may also be utilized as describedherein.

The image processor 104 preferably includes a microprocessor and memorystoring static information and dynamic information, along with softwarethat is operable to receive the angular position data from the tiltsensor 105 and make adjustments to the target image display basedthereon. Thus, changing the tilt angle, for example via aclockwise/counterclockwise rotation of a weapon attached to the aimingdevice 100, while the weapon is pointed or aimed along an axis throughthe weapon's barrel, may facilitate control of one or more aimingfunctions associated with the device. In alternative embodiments, thiscontrol and adjustment functionality of the tilt sensor may be replacedwith or supplemented by a button 105 a, switch, knob, or otherimplement.

The static information stored in the image processor 104 memory includescoordinates of the optical focal point location on the image sensor 103.Since the image sensor 103 is a two dimensional array of photositesknown as pixels, the x-y coordinates of the focal point of the lens onthe array defines the reference position of the center of the image fordisplay. These coordinates are burned into nonvolatile memory of theimage sensor

In the illustrated embodiment of FIGS. 1 and 2, changing the tilt anglemay control such aiming functions as field of view adjustment, dropcorrection, and/or windage correction. A threshold tilt angle may definethe separate functions of the aiming device 100. In one embodiment, theuser may control the field of view (i.e., the effective magnification)of the target image displayed by applying a tilt angle greater than thethreshold angle to the aiming device 100. When the tilt sensor 105senses that the tilt angle is greater than threshold angle in eitherdirection, the image processor 104 may respond by adjusting the field ofview. Whether the field of view is increased or decreased, and the rateat which it does so, may depend on the direction and magnitude of thetilt angle.

In one embodiment, the threshold tilt angle is 10 degrees. Thus,applying a tilt angle of 30 degrees to the right (i.e., clockwise) maycause the field of view to rapidly decrease (i.e., increasing themagnification power), thereby rapidly causing the objects in the targetimage to appear larger to the user. Conversely, applying a tilt angle of15 degrees to the left (i.e., counterclockwise) may cause the field ofview to slowly increase (i.e., decreasing the magnification power),thereby slowly causing the objects in the target image to appear smallerto the user.

The field of view of the target image may have limits determined by theresolution of the image sensor 103 and the resolution of the imagedisplay component 109. For example the image sensor 103 may have aresolution of 2560×1920 pixels and the image display component 109 mayhave a resolution of 320×240 pixels. The minimum field of view of thetarget image (i.e., maximum magnification) may thus be reached when thedata from one pixel on the image sensor 103 controls the output of onepixel on the image display component 109. Thus at maximum magnificationin the present example, the image display component 109 may display oneeighth of the data collected by the image sensor 103. The maximum fieldof view of the target image (i.e., minimum magnification) may be reachedwhen the image display component 109, having 320×240 pixels, displaysall the data collected by the image sensor 103 having 2560×1920 pixels.Thus at minimum magnification in the present example, data from blocksof pixels collected by the image sensor 103 are combined in a processcalled “binning” and are then sent to control one pixel on the imagedisplay component 109. In order to perform the range finding functionwith a high degree of resolution, the field of view of the target imagemust be progressively altered between maximum and minimum in smallsteps. Thus, the field of view of the image sensor 103 will vary from2560×1920 pixels to 320×240 pixels in small steps, and the resolution ofthe image displayed by the image display component 109 will remain fixedat 320×240 pixels. Thus, in one exemplary embodiment, the aiming devicehas a variable magnification ratio of 8 to 1. Again, one or more buttons105 a, knobs, or switches may also perform the adjustments describedabove in association with the tilt sensor 105.

Referring now to FIG. 2, one embodiment of a target image overlay 200 isillustrated. The microprocessor 104 may superimpose the target imageoverlay 200 on the displayed target image. The target image overlay 200displays information to the user which may facilitate aiming of theweapon. In the illustrated embodiment of FIG. 2, the target imageoverlay 200 includes crosshairs 201, range circle 202, crosswindcorrection symbol 203, range number 204, and tick marks 205. Thecrosshairs 201 are used to define an aiming position within the targetimage. The range number 204 displays the range. The units of measure ofrange can be yards or meters selectable by the user. The crosswindcorrection symbol 203 in conjunction with tick marks 205 indicates theamount of crosswind corrected for in miles per hour or kilometers perhour. With optional English units chosen, the overlay 200, as shown,indicates that a crosswind of 3 miles per hour coming from the right isbeing corrected for, and a bullet drop calculated for a distance totarget of 525 yards is being corrected for.

The illustrated target image overlay 200 includes a ranging element 202.In the depicted embodiment, the ranging element 202 is a range circle,but other element shapes may be utilized. The aiming device 100 maymeasure the distance to a target (i.e., range) via the “Stadiametricmethod” using range circle 202. The range circle 202 represents apredetermined target size. To determine the range to the target, thefield of view may be adjusted (e.g., by applying a tilt angle of greaterthan 10 degrees) while the size of the range circle 202 is heldconstant, until the image of the target appears to completely fill therange circle. Alternatively, if present on the aiming device 100, abutton 105 a may be pressed, a turret rotated, etc. The image processor104 may then calculate the distance to the target using trigonometry.For example, three points consisting of the visible top of a target, thevisible bottom of a target, and the front lens 120 define a righttriangle. The distance from the top to the bottom of the target definesa first side of the triangle. The range circle provides a measurement ofthe angle opposite the first side. Thus the, image processor 104 maycalculate for the length of the adjacent side of the triangle, i.e., thedistance to the target.

At very long distances to the target, the image of the target may not belarge enough to fill the range circle 202 even at maximum magnification(i.e., minimum field of view). Thus, in one embodiment, when maximummagnification has been reached, the image processor 104 may begin toreduce the size of the range circle 202 in response to continued inputto reduce the field of view (e.g., continuing to hold the aiming device100 at an angle beyond the threshold angle). Thus, range finding may befacilitated even at distances beyond the maximum magnification. Thisprocess is further described below.

The effect of gravity on a bullet (i.e., bullet drop) may be calculatedand corrected for by the image microprocessor 104, based on suchvariables as the range and ballistic data related to the bullet. Theballistic data may be input and stored in the aiming device 100.Examples of such inputs are described further below with reference toadditional exemplary embodiments. To facilitate bullet drop correction,the image processor 104 may shift the target image up relative to thecrosshairs 201, based on the calculated bullet drop, thereby causing theshooter to effectively aim at a point above the target although theimage will appear to the viewer to be centered about the crosshairs. Inother embodiments described below, the image processor 104 may display aregion of interest about a projectile at a certain distance from theshooter. The shooter would then be required to raise the weapon so as toalign the crosshairs on the target. This action corrects for bullet dropat any point along the projectile path.

The effect of wind on a bullet (i.e., cross-windage) may be calculatedand corrected for by the image processor 104, based on such variables asthe range, ballistic data, and ambient wind conditions at the time offiring. The ambient wind conditions may be measured or estimated usingtechniques known in the art. The cross-windage may be input into theimage processor 104 by applying an appropriate tilt angle to the aimingdevice 100. To facilitate cross-windage correction, the image processor104 may shift the target image horizontally relative to the crosshairs201, based on the calculated or known cross-windage, thereby causing theshooter to aim at a point upwind of the target. In other embodimentsdescribed below, the image processor 104 may display a region ofinterest about a projectile at a certain distance, based on thecross-windage. The shooter would then be required to move the weapon soas to align the crosshairs on the target. This action corrects forcross-windage at any point along the projectile path.

The user may control the cross-windage correction function by applying atilt angle of less than the threshold angle to the aiming device 100.The magnitude and direction of the tilt applied to the aiming device 100may control the magnitude and direction of the cross-windage input, thuscontrolling the cross-windage correction. For example if the thresholdtilt angle is 10 degrees, a tilt angle of 5 degrees to the right (i.e.,clockwise) may correspond to a cross-windage correction appropriate tocompensate for a 10 mph wind coming from the user's right side. Whereas,a tilt angle of 3 degrees to the left (i.e., counterclockwise) maycorrespond to an appropriate cross-windage adjustment to compensate fora 7 mph wind coming from the left.

The crosswind correction symbol 203 may facilitate cross-windagecorrection by allowing the user to more precisely input thecross-windage. The image processor 104 may cause the crosswindcorrection symbol 203 to slide left and right relative to the crosshairs201 in response to the magnitude and direction of the tilt angle,thereby indicating to the user the magnitude and direction of thecross-windage input being communicated to the image processor 104.

In addition, the image processor 104 adjusts the left to right positionof the displayed target image such that the target remains centered inthe crosshairs even though the line of sight of the weapon is correctedfor the cross-wind indicated by the correction symbol 203. For example,in the exemplary illustration of FIG. 2, the cross-wind correctionsymbol 203 indicates a right-to-left cross-windage input of 3 units(e.g., mph) while the weapon barrel alignment (i.e., actual point ofaim) is automatically right adjusted for this 3 MPH cross-wind becausethe display image seen by the shooter is shifted appropriately.Therefore the shooter must maintain this 3 unit tilt while firing theweapon to automatically correct for the cross-wind. In alternateembodiments, the tilt need not be maintained as the shooter may returnthe firearm to the upright position prior to firing.

In order to initially align the device 100 on a weapon, such as a rifle,first it must be mounted on the weapon and “sighted in” at a knowndistance. The sequence of operations is outlined in FIG. 19. Thisprocedure is used to compensate the device for mechanical alignmentvariations with respect to the weapon barrel. A first verticaladjustment is called correction for mechanical “elevation” at areference distance. Typically for a rifle this is done at a targetdistance of 100 yards. A second adjustment, to compensate for horizontalvariation in mounting is called mechanical “Windage”. For the device100, these adjustments are made in software resident on an externaldevice such as a laptop, iPad, smartphone or PC that is connected to themicroprocessor 104 in the device 100.

Initially default values assuming perfect barrel alignment, and anexpected muzzle velocity (MV) value and expected ballistic coefficient(BC) are loaded as defaults in the device 100, shown as operational step1101 in FIG. 19. Next, the weapon is taken to a target range where atarget is placed at a known distance, for example, 100 yards, and thedevice 100 is aimed at that target in operation 1102. Preferably this isdone when there is no cross-wind to affect the corrections being made.Then in operational step 1103 a first test shot is fired with the device100 vertical (no tilt) and aimed such that the crosshairs are centeredon the target image. In operation 1104 the bullet impact deviation fromtarget center is measured and recorded. In operation 1105 a second testshot is made and in operation 1106 the bullet impact deviation fromtarget center is recorded. These test shots are repeated several timesin operation 1107. In operation 1108, all of these recorded deviationvalues are entered into the software to generate mechanical Elevationand Windage correction values for the apparatus 100 on the particularweapon. Finally, in operation 1109, the software determined Elevationand Windage correction values for the apparatus 100 are downloaded tothe scope device 100 via its USB port.

In order to provide proper muzzle velocity (MV) and ballisticscoefficient (BC) data that is tailored to the weapon, additional testfirings at various distances are required. These operations areexplained with reference to FIG. 20. These steps are the same as in FIG.19 through step 1208. In operation 1209 the previous steps are repeatedfor several different target distances. The deviations are then enteredin software in operation 1210 to generate a best fit of the data andproduce accurate muzzle velocity and ballistics coefficient data for theparticular cartridge being fired in the weapon. These values are thendownloaded into the device 100 in operation 1211.

The software code utilized to generate the MV and BC data is based onNewtonian physics equations for projectiles that are well known.Exemplary equations for this purpose may be found in Modern PracticalBallistics, by Arthur J. Pejsa, Kenwood Publishing, 2nd edition. Oncethese values of MV and BC are known for a particular weapon/targetingdevice combination, and downloaded into the image processor 104,operation of the device 100 is straightforward.

In operation, the user of the device 100 simply aims the weapon at atarget, tilts the weapon more than 10 degrees counterclockwise tovisually zoom in on the target, then, when appropriately sized in thedisplay, return the weapon to vertical and tilts the weapon eitherslightly left or right, depending on the perceived cross-wind, and takesthe shot. Range is corrected automatically via the microprocessorshifting the display image up or down. The crosshairs remain centeredand the range correction is automatically provided and displayed.Cross-windage correction is automatically made by the shooter tiltingthe weapon to his or her estimate of the desired target offset providedby the cross-wind correction symbol 203 in the image display shown inFIG. 2. The target image is automatically shifted right or left in thedisplay so that the crosshairs remain centered and the shooter aims atthe displayed image with the crosshairs centered and takes the shotwhile maintaining the tilt desired, thus correcting for cross-winds.

Referring now to FIGS. 3-4, a second embodiment of an aiming device 300is illustrated. In the illustrated embodiment, the apparatus 300includes an elongated, hollow, tubular housing 301 having a front endand rear end. The housing may be fabricated from anodized aluminum orthe like. A front lens 302 and an image sensor 303 are mounted in asealed unit together proximal the front end of the housing 301. Thefront lens 302 is mounted so as to focus light from a target onto theimage sensor 303. The front lens 302 and sensor 303 are part of a sealedinterchangeable camera module 319. This image sensor 303 is mounted on acircuit board and preferably includes a sensor, an image processor andnonvolatile memory.

A microprocessor 304, pressure and temperature sensors (not shown), atilt sensor 305, and batteries 306 are mounted to a circuit board 326 ina control/display module 308. The image sensor 303, temperature,pressure, and tilt sensor 305 are in electrical communication with themicroprocessor 304 as described below.

The control/display module 308 and an image display component 309 areremovably mounted proximal the rear end of the housing 301. The imagedisplay component 309 is in electrical communication with themicroprocessor 304. The housing 301 also includes an integral mountingsystem 311 for the purpose of mounting the aiming device 300 to a weapon(e.g., a rifle).

The aiming device 300 may include some or all of the features of thefirst embodiment of the aiming device 100 including, for example, suchfeatures as field of view adjustment, bullet drop (range) correction,and/or cross-windage correction. In addition, the aiming device 300preferably includes interchangeable camera modules 319 consisting of thefront lens 302 and image sensor 303 in a lens barrel 320. The imagesensor 303 is mounted normal to the lens axis on a circuit boardfastened to a rear end of the barrel 320 and is preferably sealedthereto. The image sensor circuit board includes a coaxially rearwardlyextending female connector 324 for receiving a blade pin connectorextending from the forward end of the control/display module 308described below.

The camera modules 319 are secured to the housing 301 via an externalthreaded collar 318 that guides and securely seats the lens barrel 320in exact registry within the housing 301, via registration surfaces 321(shown in FIG. 9). This interchangeable camera module feature permitsone targeting apparatus or device 300 to be utilized in a variety ofdifferent circumstances such as long range or short range situationswithout the need to re-sight in a different camera module 319. This canbe very advantageous to a user.

Referring now to FIGS. 5-8, one embodiment of a removablecontrol/display module 308 is illustrated. The control/display module308 is removably mounted to the rear end of the elongated tubularhousing 301 by a collar 307. Removal of the control/display module 308from the tubular housing 301 may facilitate battery replacement and/orfacilitate configuration of device settings, as described below. Thecollar 307 may employ bayonet type, threaded, or any other suitablemounting system that can maintain mechanical connection betweencontrol/display module 308 and the tubular housing 301 during the firingof the weapon.

The front opening of the collar 307 fits over the outer surface of therear end of the tubular housing 301. The outer surface of the rear endof the tubular housing 301, in this exemplary embodiment, includes anannular groove. The inner surface of the collar 307 includes a annularrib configured to fit within the groove such that the collar 307 isrotatably mounted to the tubular housing 301. The inner surface of therear opening of the collar 307 is threaded. The outer surface of thefront end of the control/display module 308 is similarly threaded suchthat the control/display module 308 may be threadably mounted to thetubular housing 301 via rotation of the collar 307. Thus, the collar 307allows the control/display module 308 to be connected and disconnectedto the tubular housing 301 without rotation of the control/displaymodule 308 in relation to the tubular housing 301. This, in turn, allowsfor use of plug or bayonet type electrical connections between thecontrol/display module 308 and the camera module 319.

The control/display module 308 includes an eyepiece lens assembly 310.The eyepiece lens assembly 310 facilitates viewing of the image displaycomponent 309. In one embodiment, the distance from the eyepiece lens inthe eyepiece lens assembly 310 to the image display component 309 may bemanually adjustable to facilitate diopter adjustment. For example, theeyepiece lens assembly 310 may be threadably mounted in thecontrol/display module 308 such that clockwise rotation of the eyepiecelens assembly 310 causes the distance from the eyepiece lens to theimage display component 309 to decrease, and vice versa.

As is best shown in FIG. 8, the control/display module includes controlportion 313 that contains a circuit board 326 to which the batteries306, a tilt sensor, a pressure sensor, and a temperature sensor areattached and which connect with the microprocessor 304 which in turnconnects to the display element 309 in the display portion 315 of thecontrol/display module 308. The front end of the circuit board 326includes a male blade connector 322 that mates with the female connector324 to solidly connect the image sensor 303 with the microprocessor 304that is mounted on the circuit board 326 when the control/display module308 is installed within the housing 301 as above described.

Separation of the control/display module 308 from the tubular housing301 allows the user to input information to be stored in electronicmemory of the microprocessor 304. Such information may include ballisticdata, for example ambient temperature, pressure, the muzzle velocity,drag, and/or ballistic coefficient associated with one or more bullettypes. In the exemplary embodiment 300, removal of the control/displaymodule 308 from the tubular housing 301, exposes a computer connectionport 312 that is in electronic connection with the processor 304 viacircuit board 326. In one embodiment, the computer connection port 312is a USB port. The control/display module 308 may thus be connected to acomputer having appropriate application software capable ofcommunicating with the processor 304, via computer connection port 312.Ballistic data for one or more bullet cartridge types may then be inputand stored in the aiming device 300 for use related to in-the-fieldbullet trajectory calculations by processor 304 to facilitate aiming ofthe weapon as described above.

Turning now to FIG. 9, one embodiment of an interchangeable lens module319 is shown. In the illustrated embodiment, the lens module includeslens barrel 320 having registration surfaces 321. The registrationsurfaces 321 facilitate proper alignment of the interchangeable lensmodule 319 in the housing 301. As noted above, the image sensor 303preferably includes nonvolatile memory. The nonvolatile memory storesthe coordinates (x,y) of the pixel within the array of pixels of theimage sensor 303 that lies along the line of sight of the camera module319 (referred to herein as the “reference pixel”). When theinterchangeable lens module 319 is installed in the apparatus 300, themicroprocessor 304 may be operable to read the coordinates of thereference pixel to establish a reference point on the target image.Thus, each of the interchangeable lens modules 319 that may be installedin the apparatus 300 is self-contained and sealed. Further, the variablecharacteristics described herein are not affected by changing of thecamera modules 319.

Due to slight manufacturing defects (e.g., lens imperfections), thisline of sight of the camera module 319 may not be exactly coincidentwith the longitudinal center axis of the camera module 319. Preferably,the reference pixel is determined as a final step in the process ofmanufacturing the lens module 319. To determine the reference pixel, theinterchangeable lens module 319 may be connected to a calibrationapparatus (not shown) that includes surfaces that mate with registrationsurfaces 321. The calibration apparatus further includes a calibrationtarget positioned such that when the interchangeable lens module 319 ismounted in the calibration apparatus, the center axis of the lens module319 is pointed at the calibration target. An image of the calibrationtarget may then be obtained via the sensor 303. The reference pixel maythen be located by analyzing the image to determine which pixel of thesensor 303 captured the light emanating from the center of thecalibration target. The coordinates of the reference pixel may then bestored (e.g., “burned”) in the nonvolatile memory of the image sensor303 via the calibration apparatus.

Referring now to FIG. 10, four exemplary menu displays provided by thecontrol/display module of the digital targeting scope are illustrated.In one embodiment of the control/display module 308, separation of thecontrol/display module 308 from the tubular housing 301 allows the userto make in-the-field selections of such functions as size of rangecircle 202, maximum zoom range and bullet type.

These functions are preferably organized into menus. For example, acartridge menu may display several cartridge types. Changing thecartridge type on the menu causes the ballistic data, MV and BC values,used in trajectory calculations by the processor 304 to correspondinglychange.

In one embodiment, the user may step through the various menus bychanging the tilt angle of the separated control/display module 308. Forexample a first menu appears at a tilt angle of 0 degrees, a second menuappears at a tilt angle of 90 degrees, a third menu appears at a tiltangle of 180 degrees, and a fourth menu may be presented at a tilt angleof 270 degrees. The user may step through the various options withineach menu via use of the push buttons 314, 316. Thus, the user may makein-the-field changes to such functions as size of range circle 202,maximum zoom range and ballistic data associated with one or more bulletcartridge types. In other embodiments, the eye sensor described abovemay be used to step through the menus. The eye sensor may registerspecific, deliberate movements of the eye and adjust the choices on themenu accordingly. For example, the eye sensor may register movement ofthe eye downward and direct a signal to the processor to highlight amenu choice below the previous menu choices. Eye movement to the left orright may select or deselect choices. A deliberate eye blink, e.g.,having a duration longer than a predetermined time, may also be used toselect or deselect an option. Actions taken by other eye movements arealso contemplated.

Turning the aiming device 100 or 300 on is preferably accomplished byremoving a front lens cover (not described) from the aiming device.Putting the aiming device in a low power standby state is accomplishedby replacing a front lens cover on the aiming device. Naturally,removing the batteries will disable the device for storage, but will noterase static information stored in nonvolatile memory.

The technologies described herein may also be used in an aiming oroptical device that displays a position of a projectile along itsballistic curve, as the zoom level increases or decreases. An exemplarycondition is presented in FIG. 11. As described above, when a bullettravels from a rifle to an intended target, several forces affect theflight of the bullet. Gravity causes the bullet to drop in elevation asthe bullet travels from the firearm to the target. If a hunter 500 isclose to his/her target 502, the bullet drops very little. Thistrajectory is close to the optical path 504 at short distances. However,improvements in firearms and ammunition have allowed hunters to targetgame from long distances. At these greater distances, gravity causes abullet to drop in elevation more significantly, as represented by theballistic path 506 in FIG. 11. Other factors also affect the flight ofthe bullet. For instance, cross-wind causes the bullet to movehorizontally along the bullet's path of flight. The compensation in anoptical device for the effect wind has on a bullet's flight is oftenreferred to as windage. Humidity, elevation, temperature, and otherenvironmental factors may also affect the flight of the bullet.

To properly sight a target from a significant distance, typical opticaldevices (that is, optical devices that use a plurality of lenses alongan optical path, without an image sensor) may be adjusted to increasemagnification along the optical path of the device. That is, an increasein magnification increases the viewed size of a target, along a straightline between the aiming device and the target. However, to compensatefor bullet drop, the user must adjust the position of a target withinthe viewfinder by lifting the firearm slightly, thereby aligning adifferent aiming element on the target, based on the range thereto. Thisextra step is often forgotten by novice (or even advanced) shooters whoare rushed or distracted, resulting in an incorrect aim. This can leadto a missed shot, or worse, a non-lethal shot. In the so-called“ballistic zoom” technology described below, the aiming device displaysa region about the projectile position at any given distance from theshooter, thus compelling the shooter to raise, lower, or otherwiseadjust the position of the firearm to compensate for bullet drop orcross-wind.

The ballistic zoom technologies described herein differ from the priorart, in that the increase in magnification (or zoom) occurs along theballistic path 506 of the bullet. For any known ballistic information(e.g., projectile caliber, muzzle velocity, cross-wind speed, etc.), theposition of the projectile is known at any distance from the firearm.The technologies described herein zoom along this ballistic path 506, asdepicted in FIG. 11. The aiming device 508 captures a field of view(FOV) (designated by lines 510). The aiming device 508 displays only aportion of the field of view 510 to the user, however. This displayedportion (also referred to as a region of interest (ROI)) is an area ofthe field of view around the position of the projectile. Multipleregions of interest 512 are depicted in FIG. 11. For example, at zeroyards from the aiming device 512 a is the area around the projectile atthat point in space. Regions of interest are depicted at 200 yards (512b), 400 yards (512 b), 600 yards (512 c) and 800 yards (512 d). A zoomvalue (described further below) is associated with a ballistic curve,thus allowing the aiming device 508 to determine the magnification for agiven range and vice versa. The displayed regions of interest 512 may beany area as required or desired for a particular application. As thebullet drops off along the ballistic path 506, the hunter 500 iscompelled to raise the firearm to keep the displayed aiming elementpositioned properly on the target 502.

FIGS. 12A-12C depict comparisons between captured field of view versusdisplayed view for an aiming device using ballistic zoom technology atvarious zoom levels. Image inversions caused by the use of lenses withinthe aiming device are not depicted. FIG. 12A depicts an image 600captured by an image sensor, such as a camera. Typically, this image 600is the full FOV of the sensor. The ROI 602 is presented to a shooter asa displayed image 604 on a display. In this figure, the ROI 602 is theentire captured image 600. An aiming element 606, such as crosshairs, issuperimposed on the displayed image 604. The crosshairs 606 indicatewhere the bullet will be located at a particular distance from theaiming device, where that particular distance is associated with a zoomlevel of the aiming device. A ranging element 608, in this case in theform of a range circle, is also superimposed on the displayed image 604.

At all zoom levels up to and including the maximum zoom level, thedisplayed size of the ranging element 608 is the same size with respectto the FOV 600 and is calibrated to a known target size. Thus, whenusing a ranging element calibrated to a six-foot target, once the targetis “fit” within the ranging element (by increasing magnification), theaiming device is able to calculate the range to the target based on theStadiametic method, as described above. Unlike prior art devices thatincrease magnification along the optical path, the ballistic zoomtechnology increases magnification along the ballistic path. Thus, sincethe ballistic path drops as distance away from the firearm increases,the displayed image 604 is derived from an ROI 602 on a lower portion ofthe FOV 600 as zoom level increases. For example, FIG. 12B depicts therelationship at 4 x zoom level. Here, the captured image or FOV 600 isunchanged from FIG. 12A. The ROI 602 is smaller than the total FOV 600and is disposed proximate a bottom region of the FOV 600. The ROI 602 isdisplayed as a displayed image 604. The size and position of the aimingelement 606 and ranging element 608 remain unchanged on the display.FIG. 12C depicts the relationship at 8 x zoom level. Again, the capturedimage or FOV 600 is unchanged from FIG. 12A. The ROI 602 is smaller thanthe total FOV 600 and is disposed at the bottom of the FOV 600. Thesensor resolution may be scaled to the display resolution by pixelbinning or other technologies known in the art. As the zoom increasespower, a smaller and smaller ROI 602 is displayed. Additionally, sincethe magnification follows the ballistic path, the ROI 602 is alwayscentered at the bullet position for that particular zoom level andassociated range. This helps ensure an accurate shot at distance.

FIG. 13A depicts a region of interest for various magnifications of atraditional optical zoom system. In a traditional zoom system, themagnification is centered on the FOV, and the ROI corresponds to acentrally located portion of the FOV. Thus at greater and greaterdistances, the user must align different aiming elements with the targetto ensure an accurate shot. Additionally, in view of the depictedcrosswind, the user must also utilize windage aiming elements tocompensate for the crosswind. In this case, the user must aim thefirearm to the left, to compensate for the crosswind moving towards theright.

In contrast, FIG. 13B depicts a region of interest for variousmagnifications of a ballistic zoom system. Here, the center of the ROIfollows the bullet ballistic curve such that at every level of zoom, thebullet position is centered in the ROI. As the zoom level increases, thecenter of the ROI moves down according to the calculated bullet drop andmoves horizontally according to the calculated bullet drift due tocrosswind. This compels the user to center the single available aimingpoint on the target to easily obtain an accurate shot.

FIG. 14 depicts a relationship between a field of view and a fixed sizeranging element. An aiming device 700 is depicted having an FOV (definedby the outermost lines 702). The inner lines 704 depict a rangingelement extent in relationship to the FOV 702. The FOV angle α is knownat any zoom level. Consequently, the ranging element 704 subtends aknown ranging element angle β at any zoom level. The user may selectfrom ranging elements that are sized to a specific target 706 size. Forexample, the user may select a circle that corresponds a target of aparticular size at a known distance (e.g., a six foot target for elk orother large game, or a three foot target for boar or smaller game).Since there is only a single range R in which the target 706 is exactlybracketed by the ranging element 704, the aiming device 700 is able todetermine the range R based on the zoom level. The aiming deviceperforms the calculation to determine the range R to the target 706.This range is used to calculate the ballistics and position the ROI. Therange R may also be displayed, along with the zoom level, crosswindspeed, or other information.

FIGS. 15-18 depict methods of sighting a target in accordance withseveral embodiments. FIG. 15 depicts a first method 800 of sighting atarget with an aiming or optical device. The method 800 begins withoperation 802 where an initial condition of an optical device isreceived. The initial condition may include a size of a ranging elementas well as a range associated with the ranging element. For example, theranging element may be based on a target of, say, six feet, and may beselected by the user, depending on the size of an expected target. Theprocessor of the aiming device associates a known raging element with aknown range, such that the range of a target that fits within theranging element is known. Ballistic information, such as muzzle exitvelocity, projectile weight or type, crosswind speed and direction,barometric pressure, inclination, tilt, ambient temperature, and otherinformation, is received in operation 804. Typically, much of thisinformation is programmed into a storage element of the aiming deviceprior to use, although crosswind speed is generally set during use. Animage, generally, the FOV, is received by an image sensor in operation806. At least a portion of this image, the ROI is displayed on a displayto the user in operation 810. Thereafter, a first zoom input may bereceived in operation 812, and a first zoom level is set. This zoomlevel corresponds to a known distance from the aiming device. The zoominput may be based on an action taken on the part of the user, forexample, actuation of a button or knob, tilting of the firearm, etc. Asthe aiming device increases in zoom level, the projectile position atthat known distance (or zoom level), along with the associated ballisticinformation, is determined in operation 814. Based on the zoom value andprojectile position, an ROI generally around the position of theprojectile may be displayed, as in operation 816. Although the displayedcrosshairs may be used for aiming, the aiming device may display asymbol such as an aiming element at the intersection of the crosshairsto further highlight the projectile position.

FIG. 16 depicts a method 850 of sighting a target once a maximum zoomlevel is of the imaging sensor is reached. Such a condition may occur ifa target is extremely far from the aiming device user and the aimingdevice has reached its maximum zoom level after performing, e.g., themethod 800 depicted in FIG. 15. The method 850 begins at operation 852by receiving a maximum zoom input that sets a maximum zoom level. Themaximum zoom level may be defined by an image sensor ROI and a displayedimage, for example, once the resolution of the image sensor ROI meetsthe resolution of the displayed image. The maximally magnified image isdisplayed at operation 854. Thereafter, a second zoom input sets asecond zoom value at operation 856. Unlike the method 800 describedabove, further zoom input after reaching a maximum zoom value reducesthe displayed size of the ranging element. Based on the zoom input orzoom level, the size of the ranging element is calculated in operation858. That adjusted ranging element is then superimposed on the maximallymagnified image in operation 860. As the aiming device zoom inputincreases, the projectile position at that known distance (or zoomlevel), along with the associated ballistic information, is determinedin operation 862. Based on the zoom value and projectile position, aregion of interest generally around the position of the projectile maybe displayed, as in operation 864. As in the method 800 of FIG. 15, theaiming device may display a symbol such as aiming element to furtherhighlight the projectile position

FIG. 17 depicts a method 900 of sighting a target. The method 500includes receiving ballistic information, all or a portion of which maybe stored in memory. An image is received from the image sensor inoperation 904. A zoom value is received in operation 906 and aprojectile trajectory is calculated in operation 908. As with themethods described above, an ROI based on the zoom value is displayed inoperation 910. In general, the ROI corresponds at least in part to theprojectile position. Although the displayed crosshairs may be used foraiming, the aiming device may display a symbol such as an aiming elementat the crosshair intersection to further highlight the projectileposition. By superimposing a ranging element on a portion of thedisplayed image, the range to the target may be determined in operation912. Other methods of determining the range may also be utilized. Once azoom input is received in operation 914, for example, by user actuationof a button, tilting of the aiming device, etc., an updated ROI may bedisplayed in operation 916.

Another method 1000 of sighting a target is depicted in FIG. 18. Here,an image received by an image sensor such as a camera is received inoperation 1002. A field of view that is a portion of the received imageis displayed in operation 1004. A ranging element having a fixed size inrelation to the displayed field of view is displayed or superimposed onthe field of view in operation 1006. A target size input is received inoperation 1008. This target size input may be a default target sizeinput (for example, for six foot high targets) or the input may bereceived from a storage device. In other embodiments, the target sizeinput is selected from a plurality of predetermined target sizes. A zoominput that sets a zoom value is received in operation 1010 and the rangeto target is then calculated in operation 1012.

The ballistic zoom technology described herein may be utilized foraiming devices that utilize image sensors such as cameras. In certainembodiments, use of ballistic zoom may be selected as an option, insteadof the traditional or default zoom (that is, a zoom system where zoomlevel or magnification increases along the optical path) describedabove. Thus, a shooter may be able to change the zoom system (ballisticor traditional) as desired for a particular scenario, user preference,etc. In still other embodiments, an optical device setting may beselected where the crosshairs depicted, for example, in FIGS. 12A-12Care not associated with the projectile position. In such embodiments,the display may present one or more aiming elements, discrete from thecrosshairs, that are associated with the projectile position at a givendistance. The ROI may be centered on the aiming element in suchembodiments.

Referring now to FIGS. 19 and 20, the aiming device 300 may be sightedin for each of up to four types of cartridge/bullet combinations to beused in the weapon. In order to initially align the targeting apparatus300 on a weapon such as a rifle, as with the first embodiment describedabove, first it must be mounted on the weapon and “sighted in” at aknown distance. The sequence of operations is outlined in FIG. 19. Thisprocedure is used to compensate the device for mechanical alignmentvariations with respect to the weapon barrel. A first verticaladjustment is called correction for mechanical “bullet drop” at areference distance. Typically for a rifle this is done at a targetdistance of 100 yards. A second adjustment, to compensate for horizontalvariation in mounting is called mechanical “windage”. For the device300, these adjustments are made in software resident on an externaldevice such as a laptop, iPad, smartphone or PC that is then downloadedto the microprocessor 304 in the device 300 via USB port 312 on theControl/display module 308 when it is removed from the housing 301.

Initially, default values assuming perfect barrel alignment, and anexpected muzzle velocity (MV) value and expected ballistic coefficient(BC) are loaded as defaults in the device 300, shown as operational step1101 in FIG. 19. Next, the weapon is taken to a target range where atarget is placed at a known distance, for example, 100 yards, and thedevice 300 is aimed at that target in operation 1102. Preferably this isdone when there is no cross-wind to affect the corrections being made.Then in operational step 1103 a first test shot is fired with the device300 held vertical (no tilt) and aimed basically horizontally such thatthe crosshairs are centered on the target image. In operation 1104 thebullet impact deviation from target center is measured and recorded. Inoperation 1105 a second test shot is made and in operation 1106 thebullet impact deviation from target center is recorded. These test shotsare repeated several times in operation 1107. In operation 1108, all ofthese recorded deviation values are entered into the software togenerate mechanical Elevation and Windage correction values for theapparatus 300 on the weapon. Finally, in operation 1109, the softwaredetermined Elevation and Windage correction values for the apparatus aredownloaded to the scope device 300 via its USB port.

In order to provide proper muzzle velocity (MV) and ballisticscoefficient (BC) data that is accurately tailored to the weapon,additional test firings at various distances are required. Theseoperations are explained with reference to FIG. 20. These steps are thesame as in FIG. 19 through step 1208. In operation 1209 the previoussteps are repeated for several different distances. The deviations arethen entered in software in operation 1210 to generate a best fit of thedata and produce accurate muzzle velocity and ballistics coefficientdata for the particular cartridge being fired in the weapon. Thesevalues are then downloaded into the device 300 in operation 1211.

This process as is described in reference to FIG. 20 must then repeatedfor up to 4 different cartridge load/bullet combinations, since the MVand BC values will be different for each combination. Once this processis completed, the device 300 will have “learned” the precise muzzlevelocity and ballistic coefficients needed for accurate operation of thetargeting apparatus 300. In order to perform accurate cross-windagecorrection calculations, we need to have range, tilt, MV, BC, and airdensity values. Range is manually set via tilting the apparatus 300 andweapon, e.g., greater than 10 degrees until the image of the targetproperly fills the image circle in the display. The gun is then revertedto less than 10 degrees, perhaps vertical if there is no cross-wind atthe time of firing. If there is a cross-wind, the shooter simply tiltsappropriately and re-aims according to the cross hairs 201 and thecross-wind correction symbol 203 in the displayed image, and takes theshot. Temperature and atmospheric pressure are both critical to accuratedetermination of air density.

It is important to note that when the control/display module 308 isinstalled within the housing 301, temperature and pressure values may nolonger reflect accurately the environmental conditions. Hence thecontrol/display module should not be installed until at the shootingsite, or at least temporarily removed when arriving at the shooting siteso that proper temperatures and pressures can be reflected. Uponarriving at the shooting site, the user may remove and reset thebatteries 306 to reset the control/display module 308, thereby causingthe pressure and temperature values to be measured and stored before thecontrol/display module 308 is re-installed within the housing 301.Because of the contacts 322, when the control/display module is fullyinstalled, both the sensor 303 and its microprocessor and themicroprocessor 304 detects that the camera module 319 is connected andtherefore knows to present video when the lens cover is removed.

In operation, the user of either of the devices 100 or 300 simply aimsthe weapon at a target, tilts the weapon more than 10 degreescounterclockwise to visually zoom in on the target, then, whenappropriately sized in the display, return the weapon to vertical andtilts the weapon either slightly left or right, depending on theperceived cross-wind, and takes the shot. Range is correctedautomatically via the microprocessor shifting the display image up ordown appropriately for the bullet drop. The crosshairs remain centeredand the range correction is automatically provided. Cross-windagecorrection is also automatically made by the shooter tilting theapparatus at an angle less than 10 degrees corresponding to an estimateof the cross wind, and aiming directly at the target in the crosshairs.This tilt causes the display image to shift right or left such thatcorrect aim remains with the crosshairs centered. The cross-windagecorrection is shown by the indicator 203 in the image display shown inFIG. 2.

Thus, there is shown and described a unique design and concept of adigital aiming device. While this description is directed to particularembodiments, it is understood that those skilled in the art may conceivemodifications and/or variations to the specific embodiments shown anddescribed herein. Any such modifications or variations are intended tobe included herein as well. It is understood that the description hereinis intended to be illustrative only and is not intended to belimitative. Rather, the scope of the invention described herein islimited only by the claims appended hereto.

While there have been described herein what are to be consideredexemplary and preferred embodiments of the present technology, othermodifications of the technology will become apparent to those skilled inthe art from the teachings herein. The particular methods of operationand manufacture and configurations disclosed herein are exemplary innature and are not to be considered limiting. It is therefore desired tobe secured in the appended claims all such modifications as fall withinthe spirit and scope of the technology. Accordingly, what is desired tobe secured by Letters Patent is the technology as defined anddifferentiated in the following claims, and all equivalents.

What is claimed is:
 1. A method of sighting a target, the methodcomprising: receiving an initial condition of an optical device, whereinthe initial condition comprises a size of a ranging element and a rangeassociated with the size of the ranging element; receiving a ballisticinformation; receiving an image from an imaging sensor; displaying atleast a portion of the image on a display; overlaying the rangingelement on the displayed portion of the image; receiving a first zoominput to set a first zoom value, wherein the first zoom valuecorresponds to a first distance from the optical device; and determininga first projectile position based on the first distance and theballistic information.
 2. The method of claim 1, further comprisingdisplaying a first region of interest based at least in part on thefirst projectile position and the first zoom value.
 3. The method ofclaim 2, further comprising displaying a first symbol corresponding tothe first projectile position.
 4. The method of claim 1, furthercomprising: receiving a maximum zoom input to set a maximum zoom value,wherein the maximum zoom value is defined by an image sensor region ofinterest and a display region of interest; displaying a maximallymagnified image associated with the maximum zoom value; receiving asecond zoom input to set a second zoom value, wherein the second zoomvalue corresponds to a second distance from the optical device;calculating a size of an adjusted ranging element; superimposing theadjusted ranging element on the displayed maximally magnified image;determining a second projectile position based on the second distanceand the ballistic information; and displaying a second region ofinterest based at least in part on the second projectile position andthe second zoom value.
 5. The method of claim 4, further comprisingdisplaying a second symbol corresponding to the second projectileposition.
 6. The method of claim 3, wherein the first symbol comprisesat least one of a point of impact at the target and a guide symbol. 7.The method of claim 1, wherein the first projectile positiondetermination operation is based at least in part on a crosswind input.8. The method of claim 1, wherein the first projectile positiondetermination operation is based at least in part on a projectileinformation input, an ambient temperature input, an inclination input, atilt input, a muzzle exit velocity input, and a barometric pressureinput.
 9. The method of claim 1, wherein the imaging sensor comprises acamera.
 10. A method of sighting a target, the method comprising:receiving a ballistic information; receiving an image from an imagingsensor; receiving a zoom value; calculating a projectile trajectorybased at least in part on the ballistic information; and displaying aregion of interest based on the zoom value, wherein the region ofinterest corresponds at least in part to the projectile trajectory. 11.The method of claim 10, further comprising determining a range to thetarget.
 12. The method of claim 11, wherein the determination operationcomprises: displaying at least a portion of the image on a display; andsuperimposing a ranging element on the portion of the image.
 13. Themethod of claim 10, further comprising: receiving a zoom input, whereinthe zoom input comprises an updated zoom value; and displaying anupdated region of interest based on the updated zoom value.
 14. A methodof sighting a target, the method comprising: receiving an image from animage sensor; displaying at least a portion of the received image,wherein the displayed portion comprises a displayed field of view;displaying a ranging element with a fixed size in relation to thedisplayed field of view; receiving a target size input; receiving a zoominput to set a zoom value; calculating a range to a target based atleast in part on the target size input and the zoom value.
 15. Themethod of claim 14, wherein the target size input comprises a defaulttarget size input.
 16. The method of claim 14, wherein the receiving thetarget size input comprises receiving the target size input from astorage device.
 17. The method of claim 14, wherein the target sizeinput is selected from a plurality of predetermined target sizes.